Human papillomavirus in tonsillar squamous cell carcinomas from Guatemala and Brazil

ObjectivesA subgroup of tonsillar squamous cell carcinoma (SCC) is associated with human papillomavirus (HPV). Nevertheless, the prevalence of HPV seems to be variable in different regions and ethnic groups. There are no reports of HPV in tonsillar carcinomas in Guatemala, and data from Brazil are scarce. The aim of this study is to analyze and compare HPV presence in samples of tonsillar SCC from these countries.Study DesignThis study describes the histologic features, expression of p16 by immunohistochemistry (IHC), and HPV by in situ hybridization (ISH) in 13 Guatemalan and 13 Brazilian patients.ResultsAll cases of tonsillar SCC from Guatemala were positive for p16, 92% expressed HPV by ISH, and 75% corresponded to the high-risk genotype 16/18. From the Brazilian patients, only four expressed p16, and all were negative for HPV.ConclusionsCases from Guatemala, which were mostly nonkeratinizing SCC and originated from the crypt/reticular epithelium of the tonsil, had high-risk integrated HPV, whereas in Brazilian cases, which were mostly keratinizing SCC that originated from the surface epithelium, there was no association with HPV.